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ZF JMS systems

Discussion in 'Technical Discussion' started by Grampstr, Aug 15, 2013.

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  1. Grampstr

    Grampstr New Member

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    Interested in installing the ZF joystick system with skyhook. Does anyone have experience with this system?
  2. captaintilt

    captaintilt Senior Member

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    JMS Joystick

    Grampstr,

    I have experience on this system on a few applications. What kind of questions are looking for, operating, or technical.

    Thanks!
  3. Grampstr

    Grampstr New Member

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    ZF JMS joystick system

    We are building a new 48 Ft Endeavour TrawlerCat. We have spec her out with Cummins diesel and the ZT JMS joystick system, there is an option to either put electric or hydraulic bow thruster. Two questions:

    1. Is it worth the extra costs for Hydraulic over Electric and why?

    2. Has any one used the Sea Keeping or sky hook option and is it worth the extra costs.
  4. Capt J

    Capt J Senior Member

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    1. Yes- this systems relies heavily on the bow thruster and with an electric bow thruster, you will be out of juice really quick.

    2. Don't know anything about sea keeping. But skyhook works out really well if you're waiting for a bridge or something like that it comes in handy.

    However the ZF system doesn't work nearly as well as with any of the pods.
  5. captaintilt

    captaintilt Senior Member

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    ZF JMS Joystick

    I agree with CAPTJ, if your going to purchase the system, definitely go with the hydraulic bow thruster, especially if your going into a Cat hull.

    The skyhook works great as well, but not as good as the pod systems, and like CaptJ said, great for bridges, or getting fenders and lines ready to moor up. It also works well for after your into your slip, you can engage it, and depending on prevailing conditions, can get off the boat to get your lines on the dock. Also, just be careful to pay attention to wind / current, etc.
  6. Capt J

    Capt J Senior Member

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    I agree with all of the above except engaging skyhook in the slip. It is not precise enough for that and skyhook can and does do some wacky maneuvers, like deciding to scoot over 20'.
  7. HTMO9

    HTMO9 Senior Member

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    It is basically not a bad system but it cant be (theoretically and physically) as precise and powerfull as a pod drive DP system. As said before, it relies very much on the bowthruster and (if extistend) the sternthruster. On a typical 80 ft boat with 45 to 50 HP bow- and sternthrusters, you need a good sized hydraulic system, which is independend of the main engines RPM and has enough power on idle already.

    On normal shaft and prop systems, as the rudders are mechanically paralleled, it is unable to produce real vectored thrust in various directions like a multi pod drive DP system. When waiting (with skyhook) in front of a bridge or a lock with a lot of current (i.e. tidal current, especially from behind or as in our case from the side) or turbulence in the water or stronger crosswinds, the systems gets a bit erratic and needs manual input or override. Postion holding on a river with constant flow is no problem at all.

    I say again, it works but do not expect the performance of an dual or quad IPS pod drive DP setup (which does it without bowthruster and hydraulic system). Depending on the GPS and compass accuracy, a quad IPS DP will park your boat vitually on a dime, regardless of current and wind. Docking the 80 ft quad IPS with the Volvo Joystick even makes my grandson look like an old saltneck :). Our retractable bowthruster is only used (extended and on stby) for docking with Med mooring in tight spots.

    The only problem, we encountered on longer DP maneuvering (after 10 to 15 minutes) with the quad IPS in calm sea, is the smell of exhaust gases comming out of the water around the boat. In no wind situations it can do the DP maneuver on the two outer engines allone. When passing the breakwater, the inner engines are switched off anyhow (Did not have a storm jet).

    Putting a boat on DP hold at the pier, jumping ashore to secure the line and leave the boat unattended, is bad seamanship. I hope, I have misunderstood that post.
  8. Grampstr

    Grampstr New Member

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    JMS systems

    Thanks everyone for your help! I do have another question. There are two other competing systems
    1. twin disc.
    2. Xenta Vessel Maneuvering Assistant Plus (VMA Plus) system.

    Does anyone have information on these systems. Is either more accurate or less expensive than the ZF system
  9. Capt J

    Capt J Senior Member

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    A power catamaran with twin inboards is super easy to run and maneuver without even a bow thruster. I think you're going overboard here with any of these systems. That being said. With a properly sized bow thruster and 2 days of practice, you should be able to put a power cat just about anywhere you want it and in any condition (docking). I can without a thruster.

    ZF seems to have the longest history with this system and would be my first choice. Twin disc would be a second one. and I'd rude out Xenta just because they lack the dealership/service network of the above mentioned companies.
  10. Capt Ralph

    Capt Ralph Senior Member

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    Capt J has it here; Service. Who is going to help you take care of it. Allot of these systems just can not be serviced by any redneck in the boons. If your cruising local, who is going to service what brand. Lean toward that product.
    If it's on a boat, it's going to need service.....
  11. Grampstr

    Grampstr New Member

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    JMS system

    Again thanks all for your candid and helpful comments. We agree the powercat is easier to handle than a mono haul. That being said we are approaching 70 and in some cases having the extra features will allow us to stay in boating another 10 years. Jumping off docks to grab a line is not as easy as before. Having a little extra time setting up before we dock or getting fuel seems like a worthy goal! It is expensive but having 10 more years on the water it is worth it to us!

    It sounds like ZF is the best bet. Hower the Twin Disc system appears to be more accurate. We are working directly with our builder and cummins who is coming out with there own system in the Spring but to late for our install. They are recommending the ZF system. Twin Disk claims they can not install do to contractual issue until January. I think ZF is taking advantage of the situation and charging more. We want the most accurate system for the best price.


    I may decide on a different engine package either Volvo or Cat to use twin disc. Yanmar does not have a tier 3 over 370 HP we currently going with a 380 HP Cummins, both Volvo and Cat have tier 3 engines we can use.


    any thoughts?

    Joe
  12. Capt J

    Capt J Senior Member

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    :rolleyes:
    Why not just install the Zues system and pods if you preference is Cummins for the engines? I would prefer Cats with the ZF system or twin disc system if I was going that route but Cummins are ok too. I'm not a big Volvo fan. They run good when they run and are reliable for a while. But if they develop an overheat issue or electronic issue, you can chase your tail over and over again trying to find the cause of it. And they've done some hokey things along the way, like plastic heat exchanger end caps on the D5's for the first year or two.... which they then went to bronze after that, but the owners with the plastic ones were left holding the bag and paying to change them after they leaked saltwater all over everything.
  13. Grampstr

    Grampstr New Member

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    JMS system

    We were first going to put the zues system in, after our builders review the zues drives weigh 900 lbs each, adding nearly a 2000 pounds to our boat. By going with a ZF or Twin Disk we save almost 1500 lbs.
  14. Capt J

    Capt J Senior Member

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    Well, you can look up the 43' Grand Banks trawler as it is outfitted with a Zues package. You can definately go with less fuel if you're going with a POD package because on a POD twin engine installation generally your fuel burn will be about 30% less if not 40% and make up the weight difference there and lower HP engines still netting the same cruise speed as before. The specs show that your boat holds 1000 gallons of fuel, with PODS you could easily go with 800 gallons of fuel capacity and have the same range. Or have the tanks split and have 2-200 (or even 100 gallon each) gallon tanks with a transfer pump and keep them empty unless you're going on a very long journey and 2-300 gallon main tanks. I would do that anyways because with twin 380hp diesels, unless you're constantly cruising and going through a lot of fuel you're going to start developing algae issues within 2 years. I know with the 310hp volvo's and 400 gallons, I could run at cruise easily 20 hours on 400 gallons capacity with a 20% reserve on the 44' Lagoon.

    Also, the weight of the engines will be less because lower HP engines will equal the same speed as larger ones with conventional drives. What is the weight of the shafts/struts/propellors in a conventional installation that won't be there? So if you're going with 380hp conventional drives, you'd have the same performance with about 300hp engines and zues. For example. 2 equal Cabo 40' SF express'. The zues boat with 600hp cruises at 32knots with 80% load. The 800HP MAN boat with conventional drives cruises at 31.5 knots at 80% load.

    Quite honestly if I wasn't going with pods, I'd skip the expense of the other system. Maybe add a bow thruster if you have to, but on a powercat the motors/propellors are spread so far apart they're a piece of cake to dock as long as you use the current to your advantage. If it makes you feel comfortable add a bow thruster......but the whole JMS package boats are clunky and maneuver in a clunky manner and I don't see the benefit compared over not having it. Plus they're going to have a lot of programming time on the boat, probably 20 hours to get it really right if they can get it right. A buddy of mine oversaw a Tiara with a factory installed ZF system and ZF spent weeks on the boat and never got it where it was right, if you went sideways with the joystick the whole boat would really lean over from the force and all kinds of wacky stuff.......

    Also, if you do have any of the JMS systems in skyhook, you're going to hear bow thruster noise throughout the boat often as it keeps using the bow thruster to maintain position. I delivered 2 Lagoon 43/44'. One from Corpus Christi, TX to Ft. Lauderdale and another from WPB to Cancun, neither had a bow thruster and never once did I see the need for one. But individual results may vary. What is your boating experience and how are you at handling a boat that size?
  15. Grampstr

    Grampstr New Member

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    JMS system

    Thanks Capt. J
    Interesting comments. Understand your suggestions and they are food for thought.

    From my research PODs have there own issues, especially in sea keeping or sky hook mode with noise and stress on the engines as they have to pivot the entire boat from the stern. I would assume you would hear and feel pods on the bow. Maintaince and the possiblitity of one of them shearing off if you are unfortunate enought to run aground, are reason we are looking into the joy stick, bow thruster, straight shaft options.

    Our 48 is on an 18ft beam, The Lagoon's you mentioned are on a 22 ft beam. Our 48 boat is nearly 18 ft above the water line, as is our 40. Though Endeavours do handle well, we feel the extra assistance of the latest technology during heavy winds and current while docking will be helpful.

    I started boating on the Chesapeake bay in the late 60's, we have owned an Endeavour TrawlerCat 40 for the last couple years and decided for our last boat to move up to the Endeavour TrawlerCat 48.
    Last edited: Aug 17, 2013
  16. Capt J

    Capt J Senior Member

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    I haven't really seen any seakeeping issues with pods, but have heard about it briefly in very very extensive seas. You do not feel the pods on the bow in skyhook mode and unless it's REALLY windy or a lot of current the system is pretty smooth at keeping place. Every maneuver in skyhook and with the pods is computer controlled so it doesn't really overstress anything, it's designed for that. As for the break-away when it runs aground, it's made for that and you just pickup the drive and replace the bolts. It sure beats hauling the boat out to replace shafts, props, struts and possibly a broken gear. Everything has it's place, but I believe pods would be a good fit for your boat. Especially if you're really considering the JMS system.....

    As for the fuel tank recommendation, I would highly consider that regardless of what you do elsewhere. You always keep your fuel fresh, transfer the older fuel out of the auxilary tanks to the main tanks, then when you fuel, the transfer tank fuel is 100% fresh and you go through the old fuel first, you could also put a racor before the transfer pump and filter it while transfering it also.
  17. Grampstr

    Grampstr New Member

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    Thanks capt J,
    I will rethink the pods, and the idea of fuel. Our boat has two 500 gallon tanks we may be able to split them. Into two 250 gallon tanks.

    Another good thing about the Endeavour's is the running gear is fully protected in a tunnel so the props and gear do not get damaged in a grounding. It appears the Pods may fit in the tunnel thus be protected as well.

    Thanks for the advice!
  18. HTMO9

    HTMO9 Senior Member

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    There is an interesting article on this site about the Zeus pod drive for an Horizon power catamaran.

    www.horizonpowercatamarans.com/news/pod-drives-fuel-efficient-high-performance-power-catamarans

    From what I find on various sites and forums, the Zeus pod drives and multihulls work very well together. As I have no personel experience with powercats, only with sailing catamarans in the 58 to 62 ft size (Catana 58 and Lagoon 620), like Capt J said before, you do not need a bow thruster on a 48 ft and bigger cat. Neither with pod drives, nor with prop and shaft. Because of the larger distance between the props, your control authority with differential power is higher than ever needed. The Lagoon I sailed, had one thruster in the starboard hull. It was never needed, the boat turned on the dime just with differental power (two Volvo D3-150). And this boat had Gori, foldable props. A power cat with fixed high scew props and bigger engines will do even better.
  19. Capt J

    Capt J Senior Member

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    If you're intent on keeping 500 gallons a side, I'd try to split them into 300 gallon main, 200 gallon transfer and use a transfer pump to transfer the 200 gallons to the 300 gallon tank. That way you can get out almost all 200 gallons and keep them dry/empty most of the time. 300 gallons of fuel for a 380hp diesel is enough for 2 full days at cruise or more most likely anyways, so personally I wouldn't even put fuel in the transfer tanks unless you were running the boat 1000 NM or got one heck of a deal on fuel. A dry tank doesn't grow algae.
  20. Capt Ralph

    Capt Ralph Senior Member

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    I'm concerned with your comment about standard running gear is protected in tunnels. Is there room for a pod to rotate in these tunnels and still get water / thrust to the wheels when facing abeam, or did I miss something (like the pods won't turn)?

    If you already have a proven design with standard running gear (shafts & struts) in a tunnel, Why complicate a good thing?
    KISS,
    rc